(a) Field of the Invention
The invention relates to a gravity tricycle, more particularly to a tricycle that can be adapted as a means of transportation, and for exercising and recreation.
(b) Description of the Prior Art
Tricycles are supported on three wheels and are hence more stable compared to two-wheeled bicycles. For those who do not know how to ride a bicycle, riding tricycle is another option. The drive structure for a tricycle is substantially the same as that for a bicycle, and includes a front pedal that rotates to drive a front toothed disk, which drives a rear wheel via a chain. A tricycle with such a drive structure relies on the force exerted on the pedals to drive the tricycle along, which requires a large amount of force, particularly on slopes. For very steep slopes, it is more difficult for the tricycle to climb, and the rider may have to get down and push the tricycle up the slope.
The primary object of the present invention is to provide a gravity tricycle that utilizes gravitational pull on the rider as a source of power for driving the tricycle in a power-saving manner.
Another object of the present invention is to provide a gravity tricycle that can be adapted for recreational and exercising purposes.
A further object of the present invention is to provide a gravity tricycle has a speed change function and a good slope climbing capability.
In order to achieve the above objects, the power-saving drive device according to the present invention includes first and second pedals, which have drive rods respectively connected to bottom edges thereof, front ends of the drive rods being pivotally disposed on a pivot shaft at the bottom edge of the front end of the rear frame such that the two pedals may move upward and downward with the pivot shaft as a fulcrum; a transmission shaft on the rear frame and having an intermediate section provided with two unidirectional flywheels corresponding to the first and second pedals such that the two flywheels drive the transmission shaft counterclockwise only, the transmission shaft being provided with a toothed disk on one side of one of the flywheels to drive the transmission chain; and first and second reciprocating chains having front ends connected to the drive rods of the first and second pedals and being wound past upper ends of the flywheels to extend rearwardly such that rear portions thereof are coupled with a connecting element that is wound around a rotary wheel to thereby establish a linking-up relationship.